Hearing aid apparatus



July 22, 1947. R, E TRESlsE ET AL Y 2,424,422

` HEARING AID APPARATUS Filed June 12, 1945 2 Sheets-Sheet 1 `luly- 22; 1947. R. E. fREslsE ET AL 2,424,422 l HEARING AID APPARATUS Filed June 12, 1943 2 Sl'xeets-SheerI 2 20j 40 55*r 26aA 40 wf "22 "fg 2M? /0 29 @d fy 55,6

, INVENTORS Bf M14/,1%

Patented July 22, 1947 UNITED STATES PATENT OFFICE HEARING AID APPARATUS Application J une 12, 1943, Serial No. 490,612

11 Claims.

This invention relates to apparatus known to the trade as hearing aids, and has for its general object to produce an apparatus of this kind wherein the batteries and allof the cooperating parts except the earphone and the cord connected thereto can be assembled within a small container, the resultant compactness and lightness of weight enabling the container and the parts therein to be Worn without appreciable discomfort and be carried in the vest pocket of the wearer.

A further object of the invention is to provide a systematic manner of connecting the terminals of the elements of a hearing aid of this type by means of straps or vbus bars, thereby eliminating the employmentof loose wires and soldered joints for effecting such connections, the manner in which these straps or bus bars are arranged and connected serving to reduce liability to short-circuiting and also serving to produce a rugged construction.

A further object of the invention is to provide, for a hearing aid of the type described, a novel manner of mounting the microphone, whereby the same will be protected against injury by shocks and also whereby undesirable vibrations, which might detrimentally affect its acoustic qualities, may be prevented.

Further and more limited objects of the invention will be pointed out hereinafter and will be realizable in and through the construction and arrangement of parts shown in the drawings hereof, wherein Fig. l represents a rear elevational view (with parts broken away) of a complete casing in which the operating parts of the hearing aid are mounted; Fig. 2 an enlarged detail in elevation of the front of the chassis, show ing the manner in which the microphone, the input and output tubes, and the various parts of the amplifier are mounted-the detail being taken on the line 2-2 of Fig. 5, the microphone being removed from its support; Fig. 3 a similar view of the rear of the said chassis, the view being taken on the line 3-3 of Fig. 5; Fig. 4 a de tail in perspective of a portion of the ear receiver cord and one of the slip connectors secured thereto; Fig. 5 a side elevational View of the chassis and the parts assembled thereon, the microphone being indicated in dot-and-dash lines; and Fig. 6 a sectional view taken on the line 6-6 of Fig. 1 and showing the chassis and the parts mounted thereon assembled within the casing and illustratingV the manner in which the microphone and its mounting cooperate with the slip cord connector of the chassis assembly in anchoring the assembly in place.

Describing the parts by reference characters, Ill denotes the front side and II the rear side of the chassis, the same consisting of a panel of insulating material of the general shape shown in the drawings. Mounted on the front side of the chassis is a microphone I2, an input tube I3, an output tube I4, a condenser block I5 containing, in this case, two condensers (one for each tube), a volume control I6 provided with an operating disk I'I, and an output inductance I8. On the rear of the panel I have provided a slip socket I9 having rails I9a provided with channels I9b extending inwardly from the opposed surfaces thereof for the reception of the side flanges 20a of the slip connector 20 shown in Fig. 4, the said connector having a cord 2| connected thereto and leading to the slip connector for the earphone (not shown). The front side of the chassis also is provided with a contact arm 22 mounted for rotation upon a shaft 23 having its opposite ends supported by and extending through the sides of a channeled bracket 24. 25 denotes a coiled torsion spring surrounding the shaft 23 and having one end anchored in one of the sides of the bracket '24 and its other end connected to the arm 22.

The chassis having the foregoing parts arranged thereon is adapted to be inserted into the upper end of a box or casing, the latter comprising a section having a front 26 and sides 2l and bottom 28 formed integral with said front, there being a back member 29 extending downwardly about one-half the length of the front member, the back member being connected integrally with the front member and having sides 33 integral with the sides 21 and an upper end 3|x integral with the upper end 3| of the front member. The box or casing also comprises a removable rear cover section comprising a lower back member 290 which is provided Iwith integral sides 300 and an integral bottom (not shown), the sides and bottom being complementary to the sides and bottom of the front section and the edges of the sides and of the bottom of the rear section being adapted to engage the corresponding edges of the sides and bottom of the front section when assembled, the bottom walls being connected by a push latch (not shown) such as shown in our application Serial No. 407,182, filed August 16, 1941.

32 denotes a shallow channel member secured to the bottom wall 28 and supporting by its opposite sides the ends of a shaft 33 on which a o swinging contact arm 34 is pivotally mounted at its lower end, the said arm being yieldingly urged upwardly by means of a torsion spring 35 mounted on the shaft 33 and having one end anchored to one of the sides of the channel member 32 and its other end secured to the arm 34. 35 denotes a contact member secured to the bottom wall 23 and 31 a Contact member which is insulated from the casing and which is carried by the chassis adjacent to and below the output inductance I8. It will be noted that'the portion of the chassis on Whichthe inductance I3 is mounted extends downwardly a considerable distance below the portion carrying the contact arm 2.2, for the purpose of affording a support for the inductance. This also enables the contact member 3l to cooperate with a relatively short A battery in a manner to be explained herein*I after.

The microphone I2, which is shown'in Figs. l and 2 as having been removedfrom its support, comprises a short cylindrical outer body having at itsfront end an outwardly projecting ange |24, by means of which it is yieldingly supported by a wire segmental loop 39 adapted to embrace the greater portionof the periphery of the side of the microphone below the said flange, resilient pads 4U of rubber or similar material being applied tothe loop and being thereby interposed between the wire of which the loop is composed and` the liange |28. The ends of the segmental loop 39 are shown as supported from the cha-ssis by substantially vertical postsv 33e, preferably formed from the wire of which the loop is composed and extending into the chassis and anchored thereby, whereby the compactness of our construction is enhanced. The front of the microphone is provided with a wire gauze cover I2b.

With the parts constructed and arranged as thus far described and with the removable lower cover section removed and with the microphone inthe position shown in Figs.. 5 and 6, the chassis andthe parts assembled'thereon can be slid within the casing by. exerting pressure upon the slip socket I9.until the latter passes beneath the back member 29, the spring suppont for the microphone yielding suiiciently to permit the chassis and the parts thereon to be slid into the position shown in Fig. 6,' it being noted'that as soon as the slip socket I9 registers with the opening 29a provided therefor in the back of the casing, the spring 39' will operate to push so much of the socketthroughthe said opening as will enablethe chassis assembly to be anchored within the upper portion of the casing with the terminals of the slip socket exposed for cooperation with the slip socket connector 20. When the chassis is so anchored, the microphone registers with a grille 260'inthe front wall of the casing (see Fig. 6). The connector 20 is retained against dislodgment, through pressure exerted thereon in a direction longitudinally of the casing, by means of a pin I9c secured to the free end of a spring I 9d which is fastened to the inner surface of the back-member 29,Y as by a rivet 291, the pin being projected through an opening 29C in said member by the said spring; the connector is retained :againstdislodgment in the opposite direction by the shoulders h.

It will be seen that the manner of mounting the microphone results in holding it seatedby spring pressure against the front wall of the casing and also enables it to cooperate with the slip socket I 9` in anchoring the chassis within the casing.

The batteries may then be inserted, the shorter A-battery, indicated at A", having one of its poles in contact with the contact 31 and its other pole engaging the upper end of the contact arm 34. The B-battery shown at BX will be inserted in place with one of its poles in engagement with the contact 36 and the pole on its upper end in engagement with the movable contact arm 22.

As shown herein, the microphone is connected to the grid and to one end of the filament of the input tube I3. The screen grid of this tube is supplied with current from the B-battery through one of the resistors 4I, 42, which resistor is bypassed by one of the condensers in the block I5. The plate of the input tube obtains its current from the B-battery through the other of the resistors 4I, 42, and is also coupled to the grid of the output tube I4 through the other of the condensers in the block I5. The resistance of the volume control I6 is shunted variably across the gridV of the output tube vand one pole of the A or filament battery. The screen grid of the output tube obtains its current directly from the full potential of the B-battery. The plate current for the output tube is supplied from the B-battery to the plate through the winding of the inductance I8, and this inductance is shunted across the two terminals of the socket I9.

In order to facilitate the systematic manner of connecting the extensions of the terminals of the elements mounted on the panel, we have employed straps on the front and on the back of the insulating chassis, those on the back being shown at 43, 44, 45 and 46 and those on the front being shown at 4l' and 48. The ends of these straps are connected to extensions of the respective element terminals by means of rivets or eyelets extending through the insulating chassis, as indicated for instance at 49 and 49a. This makes possible the rapid wiring of the unit by a machine or hand tool and without soldering. Some of the straps on opposite sides of the chassis are also connected by these rivets or eyelets, the top of the strap 48 being connected to one end of the strap 43 by one of the rivets or'eyelets 49ar and the strap 45 being` connected to an angle bracket 240 which supports the channeled member 24, thel base of the said angle bracket being secured to the chassis and being connected to one end of the strap 45 by others ofthe rivets or eyelets 49a. It will be noted that the straps 43, 44, 45 and 46 extend substantially parallel to one another and that the straps 41 and 48 on the opposite side of the chassis extend at a different angle from the straps 43'46. This accomplishes a saving in the thickness of chassis assembly, and their arrangement prevents electrical contact interference between the multiple strap connectors. It will be noted further that, due to this utilization of the straps, the employment of loose wires for connecting the extensions or the terminals of the various elements is practically eliminated.

Furthermore, the use of straps in the manner described herein enables them to be connected in their respective lcircuits by a machine or hand tool.

While we have shown andY described a hearing aid apparatus embodying only two tubes (I3 and I4), it is within the purview of our invention to employ a larger number of tubes, with corresponding changeA in arrangement of parts and circuits.

Having thus described our invention, what we claim is:

1. An apparatus of the character described comprising a casing having an upper closed portio-n provided with a rear wall section and affront wall and with integral side and top walls,` the front wall extending downwardly below the rear wall section and having integralV sides extending below the upper closed portion and provided with an integral bottom wall, a chassis having hearing-aid elements thereonincluding a microphone and means resiliently supporting and spacing the latter from the front of said chassis, a socket connector secured to the rear oi said chassis, and one or more outwardly extending members projecting rearwardly therefrom, there being an opening provided in-v the said rear wall section for the rece-ption of said member or members and the normal distance between the front oi said microphone and the said member or members being greater than the depth of the upper portion of the said casing whereby the chassis and the hearing aid elements may be slid within the upper closed portion of the casing with the means which resiliently support the microphone being subjected to compression, said resilient means serving, when the chassis is properly positioned,`to press the said connecting member or members on said chassis through the opening provided therefor in the rear wall section thereby to retain the chassis and the parts thereon in position.

2. An apparatus oi the character described comprising a casing having relatively iixed and movable sections, the said sections, when united, forming a complete casing and having jointly front and rear walls, to-p and bottom walls and side walls, a chassis having hearing aid elements thereon including a microphone and means resiliently supporting and spacing the latter from the front of said chassis, and a socket connector secured to the rear of said chassis, and comprising one or more outwardly extending members projecting rearwardly therefrom, there being an opening provided in the rear wall of the said casing for the reception of said connecting member or members, the normal distance between the front of said microphone and the said connecting member or members being greater than the depth of the said casing whereby the means resiliently supporting the microphone will serve, when the chassis is properly positioned within the casing, to press the said connecting member or members through the opening provided therefor in the rear wall thereby to retain the chassis and the parts therein in position.

3. An apparatus oi the character described comprising a casing having relatively Xed and movable sections, the said sections, when united,

forming a complete casingand having jointly front and rear walls, top and bottom walls and side walls, a chassis having hearing aid elements thereon including a microphone and means for supporting and spacing the latter from the front of said chassis, a socket connector secured to the rear of said chassis and comprising one or more outwardly extending members projecting rearwardly therefrom, there being an opening provided in the rear wall of the said casing for the reception of said outwardly extending member or members, and spring means serving, when the chassis is properly positioned within the casing, to press the said connecting member or members through the opening-provided therefor in the rear wall thereby to retain the chassis and the parts therein in position, and cooperating contacts for one or more electrical power supplying units carried by the said chassis and the Said casing.

4.l An apparatus of the character described comprising a casing having relatively xed and movable sections, the said sections, when united, forming a complete casing and having jointly front and rear walls, top and bottom walls and side walls, a chassis of insulating material having hearing aid elements thereon having one side of greater length than the other and a lower end connecting said sides and providing vertically spaced supports,"a contact arm pivotally mounted on the lower portion of the support nearer the top of the said chassis and spring means for imparting rotary movement to said arm, a cooperating contact carriedby the bottom of the said casing, a iixed contact carried by the lower portion oi the support which is more remote from the top of the chassis, a cooperating contact arm pivotally supported at its lower end, by the bottom wall of the said casing and spring means for imparting rotary movement to said arm, there being a B-battery removably supported between the first mentioned pair of contacts and an A battery removably supported between the second mentioned pair of contacts.A

5..An apparatus of the characterV described comprising a casing having front and rear walls, top and bottom walls and side walls, a chassis. having hearing aid elements thereon including a microphone, and means resilientlyA supporting and spacing the microphone from the front of said chassis, said means including a spring wire loop forming a seat for said microphone, the ends of said loop being secured to said chassis.

6. In the apparatus set forth in claim 5, the microphone having a circumferentially extending iiange adjacent to its front end adapted to seat upon said loop and the ends of the loop being inserted into said chassis and anchored thereto.

7. An apparatus of the character described comprising a casing having relatively fixed and movable sections, the said sections, when united, forming a complete casing and having jointly front and rear walls, top and bottom walls and side walls, a chassis of insulating material having hearing aid elements thereon having one side of greater length than the other, the bottom of the chassis comprising vertically spaced side sections, a contact arm pivotally supported by the lower portion of the upper side section of the said chassis and spring means for imparting rotary movement to said arm, a cooperating contact .carried by the bottom of the said casing, a fixed contact carried by the lower portion of the lower side section of the said chassis, a contact arm pivotally supported at its lower end by the bottom wall of the said casing and spring means for imparting rotary movement to said arm, there being a B battery removably supported between the iirst mentioned pair of contacts and an A battery removably supported between the second mentioned pair of contacts.

8. An apparatus of the character described ycomprising a casing having relatively xed and movable sections, the said sections, when united, forming a complete casing and having jointly front and rear walls, top and bottom walls and side walls, a chassis of insulating material having hearing aid elements on opposite sides thereof and located in the upper `portion of said casing and extending longitudinally of said casing with its bottom spaced from the bottom of said casing, and contacts carried by the lower end of said chassis and the lower portion of the said casing respectively for the reception of power supplying units. i

9. An apparatus of the character fdescribed comprising a casing having relatively iixed Aand movable sections, the said sections, when united, forming a complete casing and having jointly front and rear walls, top and bottom walls and side walls, a chassis of insulating material having hearing aid elements on opposite sides thereof and located in the upper portion of said casing and extending longitudinally of said casing with its bottom spaced from the bottom of said casing, pairs of opposed contacts carried by the lower end of said chassis and the lower portion of said casing, each pair comprising a xed contact and a resiliently swinging arm contact, and a power supplying unit interposed between each of said pairs of contacts.

10. An apparatus of the character described comprising a `casing having relatively xed and movable sections, the said sections, when united, forming a complete casing and having jointly front and .rear walls, top and bottom walls and side walls, a chassis of Yinsulating material removably mounted within -the said casing and having hearing aid elements thereon and Vhaving one side of greater length than the other and a lower end connecting said sides and providing vertically spaced supports, a contact Amounted on the lower portion of the support nearer the top of said chassis, a cooperating contact'carried by the said casing below the iirst mentioned contact, a contact carried by the lower portion of the support which is more remote from the top of the chassis, a cooperating contact carried by the said casing below the third contact, there being a B-battery removably supported between the first mentioned pair of contacts and an A-battery removably supported between the second Vmentioned pair of contacts.

11. In the apparatus set forth in claim 10,

Y one of the hearing aid elements being mounted adjacent to the bottom of the support which is more remote from the top of the chassis.

RALEIGH E. TRESISE. PAUL D. KENDALL.y

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

